성주분지의 형성과 지표 기복 특성 = Formation of the Seongju Basin and Topographic Features

다국어 초록 (Multilingual Abstract)

This study delineates the spatial extent of the Seongju basin within the Baekcheon watershed in the Seongju-gun, Gyeongbuk Province, aiming to elucidate the cause and timing of its formation and to understand topographic features within the basin. The Seongju basin is surrounded by mountains ranging from 300 to 700 meters in all directions except for the southeast boundary where a narrow valley, formed by the Stream Baekcheon, flows water into the River Nakdong. Around the basin, gneiss from the Precambrian time is widely distributed, intruded by the Mesozoic biotite granite in the north of the basin and by the Mesozoic granodiorite in the floor of the basin. Restrained by geology, topographic features in the basin are characterized by high altitude and steep slopes in the gneiss areas and gentle slopes and hills in the granodiorite areas. The results of fieldwork have shown that the weathered soils of granodiorite are well-represented in the hilly areas, and core stones, typically developed in a deep weathering process underneath the surface, are deposited on the surface. These findings support that the Seongju basin is an erosion basin formed by differential erosion between bedrocks. The timing of its formation is estimated to be after the Tertiary tilted flexural mode took place during the Cenozoic era after the granodiorite was deep-weathered. This study offers valuable insights into the topographic features of the Seongju Basin and contributes to enhancing our understanding of people living in the basin.